Wire deflector and wire saw

ABSTRACT

A pivotable wire deflector  19  for a saw wire  3  of a wire saw  1  has a deflection roller  32 , a pivot joint  60  and a clamping and spreading mechanism. The defection roller  32  has a running groove  45  for guiding the saw wire  3  of the wire saw  1 . The pivot joint  60  has a rotary bearing block with a cylindrical receptacle  65 , and a tube  63  which is arranged so as to be rotatable in the cylindrical receptacle, wherein the deflection roller  57  is attached to the one of rotary bearing block  62  or tube  63 . A clamp  70  is fastened to the rotary bearing block  62  and arranged so as to enclose the tube  63 . A lever  68  can be moved manually between a first position and a second position.

FIELD OF THE INVENTION

The present invention relates to a wire deflector and to a wire saw.

SUMMARY OF THE INVENTION

A pivotable wire deflector according to the invention for a saw wire ofa wire saw has a deflection roller, a pivot joint and a clamping andspreading mechanism. The deflection roller has a running groove forguiding the saw wire of the wire saw. The pivot joint has a rotarybearing block with a cylindrical receptacle, and a tube which isarranged so as to be rotatable in the cylindrical receptacle, whereinthe deflection roller is attached to the one of rotary bearing block ortube. A clamp is fastened to the rotary bearing block and arranged so asto enclose the tube. A lever can be moved manually between a firstposition and a second position.

The clamping and spreading mechanism reduces, in response to the lever,in the first position, an inner circumference of the clamp to a firstcircumferential length and increases, in the second position, the innercircumference of the clamp to a second circumferential length. The firstcircumferential length is smaller than the second circumferentiallength, and the clamp bears with the first circumferential length with acontact surface against the tube.

Fixing a wire deflector is typically, including in dusty environments,to be realized by means of different measures. However, the release ofsuch a fixing as a rule requires a tool, since the fixing is gummed upby the ingress of dust and slurry. The wire deflector according to theinvention provides for the clamp to be actively spread apart in thereleased, second position by increasing the circumference. The user canintroduce the force for spreading apart by way of the lever. The leverexerts, in the first position, a pulling force for reducing thecircumference of the clamp and, in the second position, a pushing forcefor increasing the circumference of the clamp.

One embodiment of the wire deflector provides that the clamp has an endwhich is movable with respect to the rotary bearing block. The clampingand spreading mechanism has a shaft which is oriented along alongitudinal axis of the tube and which has an eccentric cam; a rotarybearing for the shaft; and a camway enclosing the cam. Either the rotarybearing of the shaft is attached to the movable end of the clamp and thecamway is attached to the rotary bearing block, or the camway isattached to the movable end and the rotary bearing of the shaft isattached to the rotary bearing block.

One embodiment of the wire deflector provides that the lever is coupledto the shaft, and the cam, in a first position of the lever, forces thecamway into a first position, and the cam, in a the second position ofthe lever, forces the camway into a second position, wherein a distanceas viewed in the circumferential direction around the tube between thecamway and the rotary bearing of the shaft is different in the firstposition than in the second position.

The clamp of the pivotable wire deflector is preferably designed to beelastically deformable. The clamp can be cylindrical in form.

One embodiment of the pivotable wire deflector provides that the clampis formed by one portion of the rotary bearing block, wherein the rotarybearing block has a gap in this portion, and this gap runs along alongitudinal axis of the tube. This portion can be delimited from anadjacent portion of the rotary bearing block by a slot which runs in thecircumferential direction of the tube, wherein the slot runs around thetube through at least 90 degrees and a maximum of 270 degrees.

A longitudinal axis of the tube is preferably arranged tangentially tothe running groove of the deflection roller. The wire deflector can besimply pivoted about the longitudinal axis without a height adaptationfor the wire guidance being necessary. The tube is preferably hollow inorder to guide the saw wire through this tube. An axis of the deflectionroller can lie in a plane perpendicular to the longitudinal axis of thetube.

The wire deflector can have a stationary foot which is attached to theother of rotary bearing block or tube.

According to one aspect of the invention, a wire saw for an endless sawwire has a housing, a wire drive, and a wire store. The wire drive isfor pulling the saw wire in a circulating direction. The wire store hasa first package of deflection rollers and a second package of deflectionrollers. The second package is mounted so as to be displaceable withrespect to the first package along a direction in order to increase alength of the saw wire stored on the wire store. A feed device exerts afeed force on the second package in the direction. The cable store isarranged downstream of the wire drive in the circulating direction. Thewire saw pulls the saw wire in the circulating direction, resulting in atensile stress on the saw wire running into the wire saw. By contrast,the saw wire running out of the wire saw is largely without tension. Therelative arrangement of wire drive and wire store allows tensioning ofthe running-out saw wire by the wire store.

One embodiment of the wire saw provides for the feed device to bepneumatically designed or to exert the feed force on the second packageby way of a mechanical spring. The introduction of the feed force bypneumatic or spring means proves to be advantageous in order to protectthe service life of the saw wire with respect to the wire tension thatquickly and strongly varies on account of inhomogeneities of thestructural element to be sawed.

One embodiment provides for the wire drive to have one or more motors.The motors are coupled to the one or more drive rollers for pulling thesaw wire in a circulating direction. The wire drive is distinguished bythe driven rollers, by contrast to the free-running rollers, for exampleof the wire store. The deflection rollers of the wire store arepreferably free-running, that is to say neither driven nor braked.

Embodiments of the wire saw provide for a wire outlet provided on thehousing to let out the saw wire. The wire store is arranged between theat least one drive roller and the wire outlet. The endless saw wire canbe guided from the wire outlet directly to the wire drive; inparticular, the saw wire can be guided rectilinearly from the wire storeto the wire outlet. The wire store can exert a tensioning force on therunning-out saw wire as far as possible without friction losses orsimilar losses.

Embodiments of the wire saw provide for a wire inlet provided on thehousing for pulling the saw wire into the housing. The wire drive isarranged between the wire inlet and the wire store. The endless saw wirecan be guided from the wire inlet directly to the wire drive; inparticular, the endless saw wire can be guided from the wire inletrectilinearly to the wire drive.

According to one aspect of the invention, a deflection roller for adeflection roller package of a wire saw has a wheel, a rotary bearingand a sealing element. The wheel has along its circumference a runninggroove for guiding a saw wire of the wire saw. The rotary bearing isinserted coaxially into the wheel. An outer sleeve projects from onelateral surface of the wheel. An inner sleeve projects from a lateralsurface opposite to the one lateral surface. A radius of the innersleeve is smaller than a radius of the outer sleeve. The sealing elementis placed on the outer sleeve or inserted into the inner sleeve.

The deflection rollers are exposed to high loading. The individualdeflection rollers have to adapt their rotational speed independently ofone another to the running speed of the saw wire, otherwise they wouldbe cut in a very short time. For the same reason, the rotary bearingshave to be very smooth-running. Dust and water clog the rotary bearings.Good sealing is therefore absolutely necessary. The conceptuallysimplest sealing seals each rotary bearing individually. This ensuresgood sealing and at the same time complete independence of thedeflection rollers. However, the sealing element in this case contactsboth stationary and rotating elements, for example an axle and thedeflection roller. The high rotational speed induces wear in the sealingelement. The solution according to the invention accepts a weak couplingof adjacent deflection rollers by the sealing element. It is shown thatthe deflection rollers can continue to rotate at a sufficientlydifferent rotational speed without being damaged by the saw wire. Bycontrast, the sealing element is exposed to virtually no loading, sincethe difference in the rotational speed of adjacent deflection rollers issmall. The rotary bearings are protected by the continuous tube formedfrom the wheels and sealing elements.

A radial cord thickness of the sealing element is advantageously greaterthan a difference between the radius of the outer sleeve and the radiusof the inner sleeve. The sealing element contacts the two adjacentdeflection rollers in each case in the radial direction.

One embodiment provides for the rotary bearing to be arranged radiallyinside the inner sleeve. The outer sleeve can project axially withrespect to the rotary bearing. The inner sleeve can project axially withrespect to the rotary bearing.

One embodiment of the deflection roller provides for the running grooveto have a plane of symmetry and for a center of gravity of the rotarybearing to be offset axially in relation to the plane of symmetry.

A deflection roller package has at least two adjacent deflection rollers(32) of the above-described deflection rollers. The inner sleeve of oneof the deflection rollers engages axially in the outer sleeve of theadjacent deflection roller. The sealing element of the deflection rollerbears radially against the outer sleeve and likewise bears radiallyagainst the engaging inner sleeve.

One embodiment of the deflection roller package is characterized in thatthe outer sleeve is spaced apart from the engaging inner sleeve.

The rotary bearings can be rolling bearings, in particular ball bearingsor needle bearings, or rolling bearings without running bodies.

One embodiment of a wire saw with a wire drive has a wire store havingat least one of the above-described deflection roller packages.

BRIEF DESCRIPTION OF THE FIGURES

The following description explains the invention with reference toexemplary embodiments and figures, in which:

FIG. 1 shows a wire saw

FIG. 2 shows a detail of a wire saw

FIG. 3 shows the wire saw

FIG. 4 shows a section in plane IV-IV of the wire saw

FIG. 5 shows a package of deflection rollers for a wire store

FIG. 6 shows an individual deflection roller of the package

FIG. 7 shows a pivotable deflection roller

FIG. 8 shows a pivot joint of the pivotable deflection roller

FIG. 9 shows a section through a clamping and spreading mechanism in afixed position

FIG. 10 shows a section through the clamping and spreading mechanism ina spread-apart position

Identical or functionally identical elements are indicated by the samereference signs in the figures, unless stated otherwise.

DETAILED DESCRIPTION

FIG. 1 shows an exemplary construction of a wire saw 1 in a side view.The wire saw 1 is suitable for example for cutting walls, blocks,pillars, buildings and other large structures or structural elements 2consisting of natural stone, concrete, bricks, or other mineral buildingmaterials. The building materials can also contain a reinforcement madeof steel. The wire saw 1 allows different cutting patterns; for example,cutting surfaces can be planar, cylindrical, conical or prismatic.

The wire saw 1 cuts the workpieces 2 by means of an endless saw wire 3in the form of a loop. The saw wire 3 has a carrier wire 4 whose endsare connected to one another to form a loop. The carrier wire 4 isflexible. The carrier wire 4 can be based for example on a wire cable.Arranged along the carrier wire 4 on its circumference are a pluralityof cutting bodies 5 for mineral building materials. The cutting bodies 5are for example made of sintered hard metal and/or provided withdiamonds. The hard cutting bodies 5 can grind or cut the mineralbuilding materials and the possibly present reinforcing bars.

The wire saw 1 is positioned away from the structural element 2. The sawwire 3 in the form of a loop is placed around the structural element 2to be severed and guided through a housing 6 of the wire saw 1. A wirestore 7 in the housing 6 allows the length of the saw wire 3 outside thewire saw 1 to be adapted to the structural element 2 and to the distancebetween the wire saw 1 and structural element 2. The wire saw 1 drivesthe saw wire 3in a circulating manner. A circulating direction 8 of thesaw wire 3, inside and outside the wire saw 1, is prescribed by a wiredrive 9 in the housing 6 of the wire saw 1. The wire drive 9 produces atensile stress on the returning portion 10 of the saw wire 3, that is tosay the portion proceeding from the structural element 2 toward the wiresaw 1. The tensile stress results in a pressing force of the saw wire 3onto the structural element 2 that is essential for the cutting of thestructural element 2 by the moving cutting bodies 5.

The housing 6 of the wire saw 1 has a wire outlet 11 and a wire inlet12. The saw wire 3 can be led out of the housing 6 through the wireoutlet 11; analogously, the saw wire 3 can be led into the housing 6through the wire inlet 12. The wire outlet 11 and the wire inlet 12 arepreferably arranged on one side of the housing 6. The wire inlet 12 ispreferably configured to be close to an underside 13 of the housing 6.With a proper setup of the wire saw 1, that is to say with the underside13 pointing in the vertical direction 14 toward the ground, the wireinlet 12 is close to the ground. The advantage in this arrangementconsists in better protection for the user should tearing occur to thereturning portion 10, which is under tension, of the saw wire 3. Theloose end of the torn saw wire 3 moves close to the ground and can bestopped by the housing 6. The wire outlet 11 is preferably verticallyspaced apart from the wire inlet 12, that is to say is at a greaterdistance from the underside 13 than the wire inlet 12.

As shown in FIG. 3 for example, housing 6 can have a chassis 15 on theunderside 13. The chassis 15 has a plurality of wheels 16, for example.The wheels 16 can be removable or blockable. The housing 6 can have onthe underside 13, in addition to or instead of the chassis 15, one ormore feet 17 which are height-adjustable or can be pivoted out. Thehousing 6 can be closed or configured as a frame. The wire drive 9 andthe wire store 7 in the housing 6 are preferably accessible from oneside such that the saw wire 3 can be inserted and wound around therollers of the wire drive 9 and of the wire store 7.

The saw wire 3 exits the housing 6 in an (outlet) direction 18prescribed by the wire outlet 11. The outlet direction 18 is for exampleperpendicular to the one side of the housing 6; for example, the outletdirection 18 is parallel to the horizontal plane, that is to say thestanding surface of the wire saw 1 or underside 13 of the housing 6. Apivotable wire deflector 19 is advantageously provided on the housing 6adjacent to the wire outlet 11. The wire deflector 19 allows the sawwire 3 to be deflected in any other direction in a constraint-freemanner. Analogously, the saw wire 3 enters the housing 6 in an (inlet)direction 20 prescribed by the wire inlet 12. The inlet direction 20 ispreferably antiparallel to the outlet direction 18. A wire deflector 21on the wire inlet 12 allows the saw wire 3 to be introduced from anydesired direction into the housing 6 in a constraint-free manner.External deflection devices 22 arranged outside the wire saw 1 can beused to guide the saw wire 3 around obstacles or according to desiredcutting lines. The deflection devices 22 can be moved, for example tocut prismatic or cylindrical shapes out of a wall.

The wire saw 1 has the wire drive 9 inside the housing 6. The wire drive9 includes one or more motor-driven drive rollers 23, 24. The driverollers 23, 24 are coupled to one or more motors 25 directly orindirectly via a gear mechanism. The drive rollers 23, 24 are driven bythe motors 25, 26 in a direction of rotation 27 about their axes ofrotation 28, 29. The direction of rotation corresponds to thecirculating direction 8 of the saw wire 3. The saw wire 3 can be wrappedaround the drive rollers 23. The drive rollers 23 pull the saw wire 3 inthe circulating direction 8 prescribed by the drive rollers 23. The wiredrive 9 ensures a pulling force on the saw wire 3. In order for thispulling force to be transmitted preferably unimpeded to the part runningoutside the housing 6, the wire drive 9 is preferably arranged directlydownstream of the wire inlet 12. Wire guidance of the saw wire 3 betweenthe wire inlet 12 and the wire drive 9 is invariable.

In the illustrated embodiment, the saw wire 3 is guided rectilinearlyalong the inlet direction 20 from the wire inlet 12 to the wire drive 9.No deflection rollers or other elements influencing the saw wire 3 arearranged between the wire inlet 12 and the wire drive 9. In otherembodiments, one or more deflection rollers can be arranged between thewire inlet 12 and the wire drive 9. The deflection rollers are freelyrotating, that is to say neither driven nor braked. Furthermore, theaxles of the deflection rollers are stationary. The length of the guidepath between the wire inlet 12 and the wire drive 9 is invariablyconstant.

The illustrated wire drive 9 has a first drive roller 23 and a seconddrive roller 24 which are arranged offset in relation to one another.The axes 28, 29 of the two drive rollers 23, 24 are preferably parallelto one another. The two drive rollers 23, 24 can have an equal-sizedcircumference and be driven at the same rotational speed. The design ofthe wire saw 1 is very compact in order to allow good transportation ofthe wire saw 1. The saw wire 3 is guided from the first drive roller 23directly to the second drive roller 24. For that reason, the directionsof rotation of the two drive rollers 23 are designed to be opposite. Thetwo drive rollers 23 can be driven by the same motor 25. Preferably,however, the first drive roller 23 is driven by a first motor 25, andthe second drive roller 24 is driven by a second motor 26. The motors25, 26 are synchronized by a motor controller 30. The motor controller30 can control a torque output of the two motors 25, 26 in such a waythat the output torque is equal over both drive rollers 23, 24. The sawwire 3 is moved without slip by the drive rollers 23. The rotationalspeed or the torque is reduced if the circulating speed of the saw wire3 is lower than the speed of revolution of the drive rollers 23, sinceotherwise the saw wire 3 would cut the drive rollers 23.

The motors 25 are preferably gas- or gasoline-driven internal combustionengines; alternatively, electric, hydraulic or pneumatic motors can alsodrive the drive rollers 23, 24.

The wire saw 1 has an adaptable wire store 7. The wire store 7 isarranged inside the housing 6. The saw wire 3 is guided via the wirestore 7. The wire store 7 makes it possible to set the guide path, andin particular its length, inside the housing 6. As a result, the wirelength of the loop 10 outside the housing 6 can be adapted. The wirelength of the loop 10 is adapted both before the start of sawing independence on the setup of the wire saw 1 and the structural element 2.Furthermore, the wire length of the loop 10 is also adapted to theprogression of the sawing. The required wire length of the loop 10becomes typically shorter with increasing cutting depth. The wire store7 compensates for the variation in the outer loop 10.

The wire store 7 is based substantially on a first package 31 ofdeflection rollers 32 and a second package 33 of deflection rollers 32.The saw wire 3 is, analogously to a block and tackle, guided inalternating fashion around a deflection roller 32 of the first package31 and a deflection roller 32 of the second package 33. The wire lengthof the saw wire 3 wound up or “stored” in the wire store 7 is dependent,inter alia, on the distance 34 between the two packages 31, 33. Thedistance 34 is settable. For this purpose, at least one of the packages31 is displaceable in the housing 6 with respect to the other package 33in a direction 35. An axle 36 of the displaceable package 33 can beguided, for example in a slotted guide 37, parallel to the horizontalplane.

The wire store 7 has a feed device 38 which exerts a feed force on thedisplaceable package 33 in the distance 34 increasing direction 35. Thedirection 35 is perpendicular to the axis of rotation 36 of thedisplaceable package 33. The user can set the feed force of the feeddevice 38. The displaceable package 33 is displaced until an equilibriumof the pulling forces in the saw wire 3 wound up on the wire store 7 andof the force spreading apart the wire store 7 has been set by the feeddevice 38. The wire store 7 thus automatically shortens the length ofthe saw wire 3 running outside the wire saw 1 in correspondence with theprogression of sawing. The packages 31, 33 are pushed apart until thesaw wire 3 bears tautly against the structural element 2.

The pulling force of the drive rollers 23 is counteracted by thefrictional forces of the saw wire 3 along the cut in the structuralelement. The tension and thus the pressing-on force is reduced counterto the circulating direction 8 of the saw wire 3. The saw wire 3 betweenthe wire outlet 12 and the structural element is therefore only slightlytensioned. The wire store 7 and its feed device 38 contribute to thetension of this portion. The tension increased by means of the wirestore 7 increases the detaching power since the outgoing saw wire 3 isalready pressed onto the structural element 2. The wire store 7 ispreferably arranged in the circulating direction 8 directly upstream ofthe wire outlet 12. In particular, no driven or braked deflectionrollers are arranged between the wire store 7 and the wire outlet 12that influence the tensile stress exerted by the wire store 7 counter tothe circulating direction 8. The saw wire 3 is preferably guidedrectilinearly from the moved package 33 to the wire outlet 12.

The tension in the saw wire 3 is dependent on the friction and thus onthe building material. Since the building material is typicallyinhomogeneous in a structural element 2, there result fluctuations inthe frictional forces and, resulting therefrom, fluctuations in the wiretension. The feed device 38 can quickly dampen this fluctuation and thusavoid overloading of the saw wire 3. A continuous adaptation of thecirculating speed of the saw wire 3 or of the pressure by the user isnot necessary.

The feed device 38 preferably includes ai-Fi resilient element. Forexample, the feed device 38 is a pneumatic feed device 38. The pneumaticfeed device 38 includes a pneumatic cylinder 39 and a reciprocatingpiston 40 guided in the pneumatic cylinder. (see, e.g., FIG. 4). Thepneumatic cylinder is fastened to the housing 6. The reciprocatingpiston 40 is coupled to the package 33. For example, the reciprocatingpiston acts on a rotary bearing of the package 33. The feed force is setby the pressure in the pneumatic feed device 38. Instead of a pneumaticfeed device, the feed device can include a mechanical spring and amechanical actuating drive, for example having a motor-driven spindle.

The exemplary embodiment illustrated has a stationary first package 31and a second package 33 which is movable to the slotted guide 37. Thefirst package 31 has an axle 41 which is anchored in the housing 6 andon which the deflection rollers 32 are placed (see, e.g., FIG. 5). Theaxle 41 is for example perpendicular to the vertical plane. Thedeflection rollers 32 are mounted in a freely rotating manner on theaxle 41. For example, the deflection rollers 32 each contain a rollingbearing 42 in order to ensure as friction-free a rotation as possible ofthe deflection rollers 32 (see, e.g., FIG. 6). The deflection rollers 32can rotate independently of one another. In particular, the rotationalspeed of adjacent deflection rollers 32 can differ, for example onaccount of diameters which differ as a result of inhomogeneous wear.During the winding-up of loose saw wire 3, different rotational speedsof inner and outer deflection rollers 32 can also occur. The package 31can in principle have any desired number of deflection rollers 32.Limited by the housing 6 and the necessary adaptation of the outer partof the saw wire 3 during sawing, the package 31 typically has from fourto eight deflection rollers 32. The second package 33 likewise has anaxle 36 on which the deflection rollers 32 are mounted in afriction-free manner. A number of the deflection rollers 32 of thesecond package 33 is identical to the number of the deflection rollers32 of the first package 31. The axle 36 can be arranged parallel to thefirst axle 41. The two axles 41, 36 are preferably inclined with respectto one another in order to be able to wind the saw wire 3 in aconstraint-free manner in alternating fashion around the deflectionrollers 32 of the first package 31 and the deflection rollers 32 of thesecond package 33. The relative inclination is low, typically in therange between 5 degrees and 20 degrees. The saw wire 3 is preferablyguided directly from one of the drive rollers 23 rectilinearly to adeflection roller 32 of the first package 31. The saw wire 3 leaves thewire store 7 from one of the deflection rollers 32 of the second package33 rectilinearly to the wire outlet 12. The first package 31 is, ascompared with the second package 33, arranged closer to the wire outlet12.

An exemplary construction of one of the packages 31 of the wire store 7is illustrated in FIG. 5, and an individual deflection roller 32 for thepackage 31 is illustrated in FIG. 6. The exemplary package 31 has fivedeflection rollers 32 which are arranged on the axle 41. The axle 41 canbe rigidly fastened in the housing 6 or be mounted so as to be rotatablein the housing 6. An orientation of the axle 41 is perpendicular to thevertical plane or tilted by a few degrees with respect to theperpendicular to the vertical plane. The vertical plane 43 is defined bythe vertical direction 44 and the horizontal longitudinal direction 18.

The deflection rollers 32 are preferably of identical configuration. Thedeflection rollers 32 can be individually exchanged if their runninggroove 45 is worn. The deflection rollers 32 are based on a wheel 132.The exemplary wheel 132 has a central hub 46, a rim 47 and a disk-shapedsupport which connects the rim 47 to the hub 46. In other embodiments,the wheel 132 can have spokes or the like instead of a solid support.The wheel 132 can be manufactured from steel, aluminum or anotherloadable material. The deflection roller 32 has a running groove 45. Therunning groove 45 runs along the entire circumference of the wheel 132.The saw wire 3 is guided to the running groove 45. The running groove 45can be formed for example by a ring made of polymer. The running groove45 is fitted onto the rim 47 of the wheel 132. Each of the deflectionrollers 32 is mounted on the axle 41 in a freely rotating manner. Forthis purpose, rolling bearings 42 are inserted into the hub 46 of thewheel 132. An inner ring 48 of the rolling bearing 42 is seated on theaxle 41. The rolling bearings 42 are ball bearings or needle bearings,for example. In the exemplary embodiment, two ball bearings arrangedwith an axial offset form the rolling bearing 42. The double arrangementallows a compact design and a high degree of stiffness against the wheel132 tilting with respect to the axle 41. The saw wire 3 coming from theother package 33 is fed to the running groove 45 slightly obliquely.This produces a resulting force along the axle 41. For this, the rollingbearings 42 can be arranged offset along the axle 41 asymmetrically tothe running groove 45. The plane of symmetry of the running groove 45that is perpendicular to the axle 41 and the plane of symmetry of therolling bearing 42 that is likewise perpendicular to the axle 41 areoffset in relation to one another.

The rolling bearing 42 must be sealed with respect to dust, slurry,water, etc. This is of especial importance particularly in the roughworking environment of the wire saw 1 and the dust, slurry, water, etc.,transported along by the saw wire 3. A loss of the free running of thedeflection wheel inevitably increases the wear, with in particular thesaw wire 3 cutting a blocked deflection roller 32 in a very short time.The deflection roller 32 seals, in each case with the adjacentdeflection roller, its rolling bearing 42. The deflection roller 32 hasan axially projecting, inner sleeve 50 on one lateral surface 49 and anaxially projecting, outer sleeve 51 on the other lateral surface 50. Thetwo hollow-cylindrical sleeves 51, 50 are arranged coaxially to the hub46. An outer radius 52 of the inner sleeve 50 is smaller than an innerradius 53 of the outer sleeve 51. The inner sleeve 50 engages in theouter sleeve 51 of the adjacent deflection roller 32. The inner sleeve50 and the outer sleeve 51 of the adjacent deflection roller 32 arespaced apart from one another. The axial spacing can be set for exampleby means of a spacer disk 54 between the deflection rollers 32.

A sealing ring 55 is inserted into the outer sleeve 51. The sealing ring55 has a Ge-Fd radial thickness 56 which is somewhat greater than thedifference between the two radii 52, 53. The sealing ring 55 seals withthe outer sleeve 51 and the inner sleeve 50 of the adjacent deflectionroller 32. The sealing ring 55 preferably contacts the two sleeves onlyin the radial direction 14 and is spaced apart at least from one of thesleeves in the axial direction. Sealing by means of the radiallyenclosed sealing ring 55 proved to be more reliable than sealing bymeans of an axially enclosed sealing ring. By virtue of the contactingsealing ring 55, there results a weak entrainment of adjacent deflectionrollers 32 at different rotational speeds. Since typically thedeflection rollers 32 have approximately the same rotational speed, thewear of the sealing ring 42 resulting from the entrainment is tolerable.

FIG. 7 and FIG. 8 show the pivotable wire deflector 19 in greaterdetail. The wire deflector 19 has a deflection roller 57 via which thesaw wire 3 can be guided. The saw wire 3 is guided by the deflectionroller 57 in a guide plane. The pivotable wire deflector 19 has a pivotjoint 60 which makes it possible to set the spatial position of theguide plane of the deflection roller 57. The plane can be oriented byany desired angle to the outlet direction 18 or the inlet direction 20.The user can thus deflect the saw wire 3 upwardly, downwardly, to theright, to the left or one of the directions situated in between. Thewire deflector can also be used for the external deflection device 22.

The deflection roller 57 can be designed substantially analogously tothe above-described deflection rollers 32. The deflection roller 57 hasa wheel 132 with an encircling running groove 45 (see, e.g., FIG. 5).The saw wire 3 is guided in the running groove 45. The wheel 132 ismounted so as to be rotatable about an axis 58. The axis 58 and therunning groove 45 are perpendicular to one another. The running groove45 and the axis 58 define the guide plane. The wheel 132 is mounted in acage 61, for example.

The pivot joint 60 connects the deflection roller 32 to the housing 6.The pivot joint 60 has a rotary bearing block 62 and a tube 63 mountedin the rotary bearing block 62 (see, e.g., FIG. 9). The tube 63 has alongitudinal axis 64 which coincides for example with the inletdirection 20 or the outlet direction 18 of the wire saw 1. The tube 63is rotatable about its longitudinal axis 64 in the rotary bearing block62. The rotary bearing block 62 has a corresponding cylindricalreceptacle 65. One diameter of the receptacle 65 has a diameter which,apart from a necessary clearance for the rotary bearing arrangement,corresponds to the outside diameter of the tube 66. In the illustratedembodiment, the rotary bearing block 62 has a foot 67 via which therotary bearing block 62 is fastened to the housing 6 of the wire saw 1.The deflection roller 57 is attached to the tube 63; for example, thecage 61 is fastened to the tube 63. In another embodiment, the tube 63can be attached to the foot 67, and the rotary bearing block 62 can beattached to the deflection roller 57.

The user can fix the pivot joint 60. For this purpose, there is provideda lever 68 which can be brought into two different positions. Theexemplary lever 68 is pivotable about an axis 69. In the exemplaryembodiment, the lever 68 can be pivoted over 180 degrees. In a firstposition, for example zero degrees, the tube 63 is fixed in the rotarybearing block 62. In a second position, for example 90 degrees, the tube63 is rotatable. A third position, for example 180 degrees, serves forreleasing the tube 66 if the pivot joint 60 is soiled. The fixing of thetube 66 is effected by way of a clamp 70. The clamp 70 encloses the tube63. The clamp 70 is fastened to the rotary bearing block 62.

A clamping and spreading mechanism 71 shortens the circumference orspreads the circumference of the clamp 70. The clamping and spreadingmechanism 71 can shorten the inner circumference of the clamp 70 to suchan extent that the clamp 70 bears with a contact surface against thetube 63. Upon fixing, the circumference of the clamp 70 is approximatelyidentical to the outer circumference of the tube 66. The clamping andspreading mechanism can additionally brace the clamp 70 in order toreinforce the fixing by way of surface pressure of the clamp 70 on thetube 63. The tube 63 is fixed. The fixing position of the clamping andspreading mechanism is for example coupled to the first position of thelever 68 (FIG. 9). The clamping and spreading mechanism 71 can cancelthe fixing by virtue of the clamping and spreading mechanism 71spreading apart the clamp 70 to a circumference at which the clamp 70bears only loosely or no longer against the tube 63. In thisfixing-cancelling position, a circumferential length of the clamp 70 isgreater than the circumferential length of the clamp 70 in the fixingposition. The cancelling position is coupled to the second position ofthe lever 68. The clamping and spreading mechanism 71 advantageously hasyet a third position in which the inner circumference can beadditionally increased (FIG. 10). Typically, the inner tube 63 gums upin the clamp 70 as a result of slurry and dirt. The additionalspreading-apart assists the release of the tube 66 from the clamp 70.The clamping and spreading mechanism 71 preferably exerts a force actingin the circumferential direction 72 on the clamp 70 not only uponreducing the circumference of the clamp 70 but also exerts a forceacting in the circumferential direction 72 on the clamp 70 uponincreasing the circumference of the clamp 70. Under the typicallyprevailing rough and dirty conditions, a simple spring action of theclamp 70 is not sufficient to securely release the clamp 70.

The exemplary clamping and spreading mechanism 71 is based on acamshaft, that is to say a shaft 73 on which an eccentrically arrangedcam 74 is arranged. The shaft 73 is mounted in a rotary bearing 75 so asto be rotatable about a shaft axis 76. The lever 68 is for examplerigidly connected to the shaft 73 and makes it possible for the user torotate the shaft 73. The shaft axis 76 is preferably parallel orapproximately parallel to the longitudinal axis 64 of the tube 66. Thecam 74 engages in a camway 77.

A rotation of the shaft 73 leads to a relative displacement of thecamway 77 with respect to the rotary bearing 75. In the illustratedembodiment, the rotary bearing is arranged on the rotary bearing block62, and the camway 77 is arranged on a portion of the clamp 70 that ismovable with respect to the rotary bearing block 62. The relativemovement of the rotary bearing 75 of the shaft 73 with respect to thecamway 77 is translated into a movement of the movable end of the clamp70 with respect to the rotary bearing block 62 in the circumferentialdirection 72 and thus into a shortening or enlarging of thecircumference of the clamp 70 and its circumferential length.

The camway 77 can be formed for example by a surface pointing in thecircumferential direction 72 (see, e.g., FIG. 9) and a surface pointingcounter to the circumferential direction 72. The cam 74 bears againstone of the surfaces in the shortening position and against the other ofthe surfaces in the spreading position. A radial distance 34 between thesurfaces and the shaft axis 76 is smaller than the radial distance 34between the cam 74 and the shaft axis 76; that is to say of the contactsurface, which contacts the surfaces, of the cam 74.

The exemplary clamp 70 is designed as one portion of the rotary bearingblock 62. The exemplary rotary bearing block 62 is likewise tubular. Theclamp 70 is formed by a gap 79 running along the longitudinal axis 64.The clamping and spreading mechanism 71 closes or widens the gap 79 inthe circumferential direction 72. The clamp 70 advantageously separatesa slot 80 running in the circumferential direction 72 from the otherportion of the rotary bearing block 62. As a result, the forces forclosing or widening of the gap 79 are reduced. The slot 80 can run forexample through more than 90 degrees in the circumferential direction72, for example through less than 270 degrees in the circumferentialdirection 72.

1-12. (canceled) 13: A pivotable wire deflector for a saw wire of a wiresaw, the pivotable wire deflector comprising: a deflection roller havinga running groove for guiding the saw wire of the wire saw; a pivot jointhaving a rotary bearing block with a cylindrical receptacle and a tubearranged so as to be rotatable in the cylindrical receptacle, whereinthe deflection roller is attached to the rotary bearing block or thetube; a clamp fastened to the rotary bearing block and enclosing thetube; a lever movable manually between a first position and a secondposition; and a clamping and spreading mechanism, the clamping andspreading mechanism in response to the lever, in the first position,reduces an inner circumference of the clamp to a first circumferentiallength and, in the second position, increases the inner circumference ofthe clamp to a second circumferential length, wherein the firstcircumferential length is smaller than the second circumferentiallength, and the clamp bears with the first circumferential lengthagainst the tube with a contact surface. 14: The pivotable wiredeflector as recited in claim 13 wherein the clamp has an end movablewith respect to the rotary bearing block, and the clamping and spreadingmechanism has a shaft oriented along a longitudinal axis of the tube andhas an eccentric cam, a rotary bearing for the shaft, and a camwayenclosing the cam, wherein either the rotary bearing of the shaft isattached to the movable end of the clamp and the camway is attached tothe rotary bearing block, or the camway is attached to the movable endand the rotary bearing of the shaft is attached to the rotary bearingblock. 15: The pivotable wire deflector as recited in claim 14 whereinthe lever is coupled to the shaft, and the cam, in a the first positionof the lever, forces the camway into a first position, and the cam, in athe second position of the lever, forces the camway into a secondposition, wherein a distance as viewed in the circumferential directionaround the tube between the camway and the rotary bearing of the shaftis different in the first position than in the second position. 16: Thepivotable wire deflector as recited in claim 13 wherein the clamp isdesigned to be elastically deformable. 17: The pivotable wire deflectoras recited in claim 13 wherein the clamp is formed by one portion of therotary bearing block, wherein the rotary bearing block has a gap in theone portion, and the gap runs along a longitudinal axis of the tube. 18:The pivotable wire deflector as recited in claim 17 wherein the oneportion is delimited from an adjacent portion of the rotary bearingblock by a slot running in a circumferential direction of the tube,wherein the slot runs around the tube through at least 90 degrees and amaximum of 270 degrees. 19: The pivotable wire deflector as recited inclaim 13 wherein the clamp is cylindrical in form. 20: The pivotablewire deflector as recited in claim 13 wherein a longitudinal axis of thetube is arranged tangentially to a running groove of the deflectionroller. 21: The pivotable wire deflector as recited in claim 13 whereinthe tube is hollow. 22: The pivotable wire deflector as recited in claim13 wherein an axis of the deflection roller lies in a planeperpendicular to the longitudinal axis of the tube. 23: The pivotablewire deflector as recited in claim 13 further comprising a stationaryfoot attached to the other of rotary bearing block or tube. 24: A wiresaw comprising a wire drive and the pivotable wire deflector as recitedin claim 13.